Thermo-magnetically operated device



Dec. 29, 1931.v P. N. Rosl-:BY 1,839,165

THERMOMAGNETICALLY OPERATED DEVICE Filed April 26, 1928 (lgs a VM@ Patented Dec. 29, 1931 Y .mHERMo-MAGNET-roALLY oPERATEnnEvIoE .Application sied .April.26;iaaiieiialfm- 213.134, ,and meezit Bnemjuay ,116, i927. g

The present invention is Aconcerned with thermoniagiietically' operated devices, is to lsay Adevices which motion is obtained by employment ,o :the principle ,that

a .magnetized'fmember ,changes its magnetic Y properties. under'the :influence .ofy heat. ',.Such devices meytakeitheerf flalrheto'r adept- ,edito havecontnuousmotion inthe Same drectiori7 or a relay .which Lwill ,move through l ysmall Idistance,0.1,alsoNan arrangement .whichf'will novebackwards and forwards Awith .an l.oscill'atirymotion.

A In one Iform ,of Vthe Vr inyention 1(':or'i'struct-ed as ,a motor `to Qperate continuouslywin lthe same `|directionya `ring .of suitable lmagnetic f material .ispivotedQso las to 'i'beffee to rexiolve inits ownplaneandisiarrangedjsothat ya IPortion offits' ycircumference y.isvin amagnetic field which tmay,glpiprovidedV either .by apermanentimegiletlerbyah.electreliegnt suitable source oi 'heat is A4applied to the ring vclose .gto ,the t,magnet sogasft'o",a'iiectl aporton of .the .ring-lying .withiifli imaeeet@ field. As this 'por'tion of fthe ,ring Vbg'ecornes heated,'its magnetic properties ,are modified andjgin general, it will.tend to lose its niagnetism.' Consequently the ring is subject to Vthe action of two unequal magnetic forces acting in opposite directions and accordingly the resultant force causes the ring to revolve. As the hot portion of the ring moves away from the vicinity of the heater it will cool and will then regain its magnetic properties; consequently a continuous motion of the ring is obtained as long as there is a sufflcient diierence of temperature between the portions of the ring in the magnetic field. It is clearly necessary that the ring shall have cooled suificiently to regain its magnetic properties by the time it again reachesthe magnet for the rotation to be continuous, and

this sets a limit to the speed of rotation, though cooling canbe facilitated by suitably designing the containing chamber.

It will be seen that a construction similar to this can be employed for closing electric contacts, sothat an electrical circuit may be closed or opened either when the source of heat becomes operative or, also, if an electromagnet is employed for providing the regainsfthem ,unimpaired :once ing.'

magnetic wh'enthis isenejrgiaed.` Sirnilarly by the ,use 'of two coilsone'yon each side p ofthe magnet, controlled by contactls'ololsed by thelring at `each extremity l of its travel, it maybe made to move baclrwaijdsand for'- wards ,n in oscillatorymanen Alternatively a restoring yspring.'zou-ld be used,"in which ,case only a single coil ,would'rbefneclhe' ring itself is .preferably .COmpQSed of nickel-i ronjwil magnetic material which doses itsnia'gneti revwith Va composition [of pijopertiesjunderthe inlucilfcejotlleat;and

'.TheiiyrQmegnetC eiellgemfe @Ording tothe rinvention,l isparti'QLlmly gs table'v Yfor driving flicker-,producing devices asusedV ,in imitation lires adaptedtofsimulatle the appear; anceof :a b urningjcoajl fire; ahdfuhan jar,- rangementwill .110W be described. .y Way 0f being ,te the fa'col* panying drawing ii'herenith ,e'ngle'guf'is a perspective "view of the ,sainfe. ln-s'aid drawing, A isa Sheet'ordiscof glass vvoffsiilofeiempl, .reference n stantially saucer shape having an irregular sufface andcpivote'dfat centregwithj its 1conveX`k slide upwards. The'glass A4 carriesfa nonmagneticframeF to' which is atta hed a 'conf sp Y alloy, constituting" the previously-mentioned ring. Adjacent totheringinone posit nis a heatin spirall formation 5and is fitted to a .grooved Ippifeeiain fortifier which is uien vfiiledgiii ,with

o. negata@as siippoieiim ajbrassffa'me ,ridguieeieerlq@iep r'rli ,and they (are .Se chase/1i .t 't

produce the desired effect when working at a dull red heat, by which means its life is prolonged.

The action of the device will be readily understood from what has already been said, but it may be traced through briefly. lVhen the current is switched on, the heater B comes into operation and heats the portion of the ring close to it so that this portion becomes non-magnetic. exerted by the magnet on the ring become unbalanced owing to the fact that a portion of the ring in the magnetic field is magnetic, while another portion is non-magnetic. Accordingly, a component is produced which serves to rotate the glass A. As soon as the heated portion of the ring moves vout of range of the heater B, it commences to cool, and bcfore it again comes into the magnetic field it has fully regained its magnetic properties. In consequence, al continuous rotation of the glass A is produced as long as the heater is in circuit. The light from the lamp G shining through the rotating glass A produces a flicker effect which is Vvery realistic and is almost entirely free from the periodic or mechanical effect so often found in devices of this nature.

It will be understood that the invention is not limited to the arrangement in which the; rotating glass is Vsaucer-shaped; if desired, a complete cylinder of glass having an irregular surface could be employed or, alternatively, a flat glass plate carrying a cylin- V drical skirt of opaque material might be made use of. A still further modification, which would however introduce some additional complication, would be the provision of two concentric glass cylinders arranged to rotate in the same direction at different speeds or possibly also in opposite directions. It is found that the above driving arrangement, While being simple and reasonably robust, provides ample power for rotating a comparatively heavy piece of glass and has also the additional advantage that it will work equally well witheither alternating or direct current.

What I claim as new and desire to secure by'Letters Patent'is:

1. For use in an imitation fire, a flickerproducing device comprising a source of light, acircular disc of glasshaving an irregular surface, said disc. directly overlying said light source to be struck by the light rays emitted thereby, mounting means for supporting said disc while permitting it to rotatein its own plane, a ring attached to the disc,.said ring beingmade of magnetic material which loses its magnetic properties on being heated, means for producing 'a magnetic field around a portion of said ring, and means for heating said ringin one portion of said field whereby the heated portion is rendered nonmagnetic and said ring and disc are rotated by the action of said field on said unheated portion of said ring.

2. For use in an imitation fire, a flickerproducing device comprising a source of light, a saucer-shaped piece of glass having an irregular surface, said disc directly,V overlying said light source to be struck by the Alight rays emitted thereby, a pivot for rotatably mounting said glass with its convex Hence the magnetic forces sideupwards, a continuousring of nickeliron alloy containing vS30-40% of nickel attached vto the circumference of said glass, a permanent magnet supported with one of its poles adjacent to va portion of said ring, an electric resistance coil located in the neld of said magnet and adjacent to saidA ring, and means for supplying current to said coil whereby the vportion of said ring adjacent to said coil is heatedusulciently to'lose its magnetic properties and said glass is rotated due to the attraction between said magnet and the portion of said ring corresponding to said heated ,portion but located on the side of said magnet remote from said coil.

3. For use in an imitation fire, a fiiclrer producing device comprising a source or light, a piece of glass having an irregular surface, said glass overlying said source of' lightv to be struck by the light rays emitted therefrom, means for mounting the glass for rotary movement to produce a flicker effect,`and a pyro-magneticmotor for rotating said glass, said motor including afmetallic ring member attached to the periphery of said glass, and fixed means arranged to cooperate with said metallic member to move the same, and thereby effect the movement of said glass.

In testimony whereof I havesigned my name' at Liverpool, England, this 13th day of April, 1928. i p

PHILIP NORTON ROSEB. 

